Grip for cable-railways



H e e h s W e e h s 2 G a d O M o W No. 585,873. Patented July 6, 1897.

2 SheetsSheet 2.

(No Model.)

0. B! MARTIN. GRIP FOR CABLE RAILWAYS.

Patnted July 6.1897.

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1 UNITE STATES PATENT OFFICE.

CHARLES B. MARTIN, OF BROOKLYN, NEl/V YORK.

GRIP FOR CABLE-RAILWAYS.

SPECIFICATION forming part of Letters Patent No. 585,873, dated July 6,1897.

Application filed February 10, 1897. Serial No. 622,753. (No modeL) Toall whom it may concern.-

-Be it known that I, CHARLES E. MARTIN, a citizen of the UnitedStates,residing in Brooklyn, Kings county, in the State of New York,have invented a certain new and useful Improvement Relating to Grips forCable-Railways, of which the following is a specification.

The invention is intended more particularly for use in situations, as onthe Brooklyn bridge, where the track is set apart exclusively forrailway use and the cable runs on sheaves at or above the surface andmay be lifted or lowered, as required. The means for raising the cableinto position to be engaged by'the grip maybe of the ordinarylongapproved style. I employ mechanism for gripping it with the requiredfirmness between gripping portions or blocks properly shaped to matchand can take hold and let go at will, and in addition I provide forantomatically liberating the cable and allowing it to sink when anyexigency shall require it.

The cable is led downward, as usual, at the end of the road. The gripshould be opened by the attendant before reaching that point. lVheneverthrough inadvertence of the at tendant or a derangement of the grip thisis not done, so soon as the cable is drawn strongly downward at the endof the road my grip automatically opens and releases it. The force withwhich the mechanism resists such automatic releasing of the cable may beadjusted between wide limits. After such automatic release of the cablethe grip automatically resumes its proper closed position ready tobeopened and closed again by the operator, as required.

The accompanying drawings form a part .of this specification andrepresent what I consider the best means of carrying out theinvention.

Figure 1 is a plan view. Fig. 2 is a corresponding verticalcross-section through the center. These figures show the grip in usetaking firm hold of the cable. Fig. 3 is a section of a portioncorresponding to Fig. 2, but showing the condition of the parts adjacentto the cable in the act of automatically liberating the cable when anexigency shall require it. The remaining figures show details detached.Fig. 4 is a cross-section, on a larger scale, of one of the grippingportions or blocks which apply directly against the cable. Fig. 5 is aplan view of the same block. Fig. 6 is a corresponding section, partlyin elevation, showing one of the backing-pieces lying immediately behindeach gripping portion or block and communicating the pressure of thegripping mechanism thereto. Fig. 7 is a corresponding plan view of thisbacking-piece. Fig. 8 is an elevation showing these parts properlyassembled and with one of the springs holding the gripping portion orblock firmly up in the ho'rizontalposition, but with liberty to yielddownward. Fig. 9 is a corresponding perspective viewof the same parts.

Similar letters of reference indicate like parts in all the figureswhere they appear.

A is a framing of cast-iron or other suitable material to be boltedfirmly on the under side of a car=-body. (Not shown.) B is a shaft heldlongitudinally therein and which forms the axis of motion for twocapacious gripping-jaws (l C, which are opened and closed by doubletoggle mechanism 11) D inclosed in a casing C and operated -by anupright shaft D, which is partially rotated in one direction and theother by the gripman actuating a rod E. So far as yet described thismechanism is of an ordinary and long-approved character and is operatedin the ordinary manner, the gripman turning the shaft D in the directionto separate the jaws O O to receive the cable and turning it in thereverse direction to grip the cable with the required degree of force toenable it to reliably move the car.

M is the cable.

It is one of the duties of the gripnian to open the grip by these meansbefore the end of the line is reached, and the cable thus liberated willdrop out of engagement and the car is stopped by the brake. (Not shown.)So long as this dutyis successfully performed as the car approaches eachend of the line my improvement will be of no effect. The strong andswiftly-running cable continues its motion irrespective of any troubleor derangement on one or more cars. It cannot be stopped in time torelieve itself or any attached cars. The cable is usually of suchstrength that there is little chance of its being broken,.but a severeabrasion at any point ICO may rupture some of the surface-wires andinduce very serious injury to this'iniportant and costly member of thesystem. Then from any cause the grip retains its hold on the cable asthe car reaches the end of the line, there will be a fracture ofsomething. This improvement provides against such mischief.

G G are the gripping portions orblocks, each having a properly-hollowedface g, slightly flared at each end and adapted to receive the cable andexert the required strong pressure thereon. These gripping-blocks haveeach a hollowed back g,which matches fairly against a correspondingcylindrical surface on the backing-piece H, which latter is firmlycarried on the corresponding jaw O and is provided with a trunnion II ateach end, which receives an arm G from the gripping-piece G and isreliably but loosely held by a binder and bolts. Each backing-piececarries two supports H which receive helical spring I, inclosingeyebolts J which are-hinged to the gripping-block by means of athrough-bolt K, which traverses eyes on the bolts and lugs on thegripping-block. The upper end of each bolt J- is screw-threaded andreceives a sufficiently-extended washer and a nut L and j amnut L. Byturning these nuts up or down the tension of each spring I may beincreased or reduced. It is important that the gripping portionsorblocks be held firmly up in the horizontal position under ordinaryconditions and yet that they be at liberty to sink into the inclinedposition shown in Fig. 3 whenever the cable is pulled down with a forcesufficient to overcome the friction and thesprings.

When such emergency occurs, the cable is drawn downward without seriousdanger of injury to itself or any other portion of the mechanism, and sosoon as liberated the gripping portions or blocks G G are drawn upwardby the tension of the springs I, exerted through the eyebolts J, totheir proper horizontal positions. The construction offers a largeamount of friction to resist the downward mot-ion by the extendedbearing between the hollowed surface g and the corresponding swelledsurface of the backing-piece subjected to the strong pressure of thegrip on the cable. This friction aids the springs I in holding up thegripping-pieces and en abling them to resist all the ordinary andextraordinary forces due to the slight inclination of the cable and toany vibrations or other agitation thereof in traversing along the road 5but when through accidental holding of the cable too long at the end ofthe road the gripping-pieces have been subjected to such intense forcethat they yield downward and discharge the cable the entire friction onthe surfaces 9 is relieved, and the friction of the arms G' on thetrunnions II being insignificant there is little more than .llSG.

ther use. The parts are in the same condition after such discharge asbefore, except that the grip is closed. It requires simply to be openedby the attendant to restore the entire apparatus to its originalcondition.

Modifications may be made without depart-- ing from the principle orsacrificing the advantages of the invention.

The supports H for the feet of the springs I may be hollowed or madeinto universal joints to allow the changes of inclination required, butmy experiments indicate that no such complication is necessary.

The head of each eyebolt J may be formed with a bearing applying fairlyagainst the under face of the support H and forming a definite stop todetermine the height of each portionor block when held up in positionforEach portion or block G may extend downward farther than shown, so as togive wider bearings against the cable when the latter is in the act ofescaping by being drawn violently downward.

I claim as my invention 1. In a grip for cable-railways, the combinationwith the gripping-jaws and mechanism for manually adjusting them in oneof two or more positions, of gripping portions carried by said jaws andcapable of an outward yielding movement independently of the jaws,adapted to release the cable when the downward pull becomes excessivewithout changing the position of the jaws, all substantially as hereinspecified.

2. In a grip for cable-railways, the combination with the gripping-jawsand mechanism for manually operating the same, of gripping portionscarried by said jaws and springs I connected to the gripping parts andstand in g on abutments H arranged to permit their automatic opening andto effect the returnof the same, independently of the adjusting means,substantially as herein specified.

3. In a grip for cable-railways, the combination with the gripping-jawsand mechanism for manually operating the same, of gripping-blockspivoted to said jaws to swing independently thereof, and connectedsprings arranged to automatically yield and again automatically restorethe blocks to an operative position, substantially as herein specified.

4. In agrip for cable-railways, the combination with the gripping-jaws.having convex bearing-faces, and mechanism for operating said jaws, ofgrippingblocks pivoted to the jaws to swing vertically, and havingconcave rear faces to move on said bearings, and spring yieldingconnections for normally holding the blocks in an operative position,substantially as herein specified.

5. In a grip for cable-railways, the combination with the gripping-jawsand mechanism for operating the same, of grippingblocks pivoted to saidjaws to swing vertically, and adjustable spring-yielding connections fornormally holding the blocks in an operative position, substantially asherein specified.

6. In a grip for cable-railways, the combination with themanually-operated grippingjaws, carrying the backing-pieces having theend trunnions and upper supports 1-1 of gripping-blocks held up byspring-yielding and suspended eyebolts J, guided in said supports, and athrough-rod K passing through the eyebolts, and also through lugs on thegripping-blocks, substantially as herein specified.

7. In a cable-grip, in combination with the gripping-jaws O, andoperating mechanism therefor, the gripping-blocksG arranged to liberatethe cable not only by the opening of the jaws, but also by yielding to asufficient downward pull of the cable, said blocks hav- CHARLES E.MARTIN.

Witnesses:

J. B. OLAUTIcE, M. F. BOYLE.

